">Nasa, with the European Space Agency, is developing a campaign to send Martian samples back to Earth.
On September 1, NASA’s Perseverance rover deployed its arm, placed a drill bit on the Martian surface, and drilled about 2 inches, or 6 centimeters, to extract a rock core. The rover then sealed the rock core in its tube. This historic event marked the first time a spacecraft has packaged a rock sample from another planet that could be returned to Earth by a future spacecraft.
Mars Sample Return is a multi-mission campaign designed to collect the carrots that Perseverance will collect over the next few years. Currently, in the design and technological development phase, the campaign is one of the most ambitious endeavors in the history of spaceflight, involving multiple spacecraft, multiple launches, and dozens of government agencies.
“Return a sample of ">March has been a priority for the planetary scientific community since the 1980s, and the potential opportunity to finally achieve this goal has unleashed a torrent of creativity, ”said Michael Meyer, senior scientist for NASA’s Mars Exploration Program based in the United States. NASA headquarters in Washington.
The advantage of analyzing samples on Earth – rather than assigning the task to a rover on the Martian surface – is that scientists can use many types of advanced laboratory technology that are too large and too complex to be. sent to Mars. And they can perform analyzes much faster in the lab while providing much more information on whether life ever existed on Mars.
“I have dreamed of having samples from Mars to analyze since I was a graduate student,” said Meenakshi Wadhwa, senior scientist for the Mars Sample Return program, which is run by NASA’s Jet Propulsion Laboratory in Southern California. “Collecting these well-documented samples will ultimately allow us to analyze them in the best laboratories here on Earth once they are returned.”
Mars Sample Return would involve several firsts aimed at settling an open question: Did life take root elsewhere in the solar system than on Earth? “I’ve worked my entire career for the opportunity to answer this question,” said Daniel Glavin, astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Glavin helps design systems to protect Martian samples from contamination as they travel from Mars to Earth.
Collecting samples from Mars and bringing them back to Earth will be a historic endeavor that began with the launch of NASA’s Perseverance rover on July 30, 2020. Perseverance collected its first rock core samples in September 2021. Credit: NASA / ESA /JPL-Caltech
Developed in collaboration with ESA (the European Space Agency), Mars Sample Return would require the autonomous launch of a rocket full of precious alien cargo from the surface of Mars. Engineers should ensure that the rocket’s trajectory aligns with that of a spacecraft orbiting Mars so that the sample capsule can be transferred to the orbiter. The orbiter would then return the sample capsule to Earth, where scientists would wait to safely contain it before transporting it to a biohazard secure facility, which is currently under development.
Before bringing Martian samples back to Earth, scientists and engineers must overcome several challenges. Here is one:
Protect Earth from Mars
Keeping samples chemically intact for rigorous study on Earth while subjecting their storage container to extreme sterilization measures to ensure nothing dangerous is delivered to Earth is a task that makes Mars Sample Return truly unprecedented.
Billions of years ago, the Red Planet could have a comfortable environment for life that thrives in hot and humid conditions. However, NASA is highly unlikely to bring back samples of living Martian organisms, based on decades of data from orbiters, landers and rovers on Mars. Instead, scientists hope to find fossilized organic matter or other signs of ancient microbial life.
Despite the low risk of bringing anything alive back to Earth, great caution is driving NASA to take significant steps to ensure that Martian samples remain sealed throughout their journey. After collecting rock cores from all over Jezero Crater and placing them in tubes primarily made of titanium, one of the strongest metals in the world, Perseverance hermetically seals the tubes to prevent the accidental release of the smallest particle. The tubes are then stored in the belly of the rover until NASA decides when and where to drop them on the Martian surface.
A sample return campaign would include an ESA sample recovery rover that would be launched from Earth later this decade to retrieve those samples collected by Perseverance. Engineers at NASA’s Glenn Research Center in Cleveland, Ohio, design the wheels for the fetch rover. The rover would transfer samples to a lander, under development at JPL. A robotic arm on the lander packs the samples into the tip of a rocket designed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.
The rocket would deliver the sample capsule to Mars orbit, where an ESA orbiter would wait to receive it. Inside the orbiter, the capsule would be readied for delivery to Earth by a payload under development by a team led by NASA Goddard. This preparation would include sealing the sample capsule inside a clean container to trap any Martian material inside, sterilizing the seal, and using a robotic arm under development at Goddard to place the sealed container in an entry capsule to Earth prior to the return trip to Earth.
One of the main jobs of NASA engineers is figuring out how to seal and sterilize the sample container without erasing important chemical signatures in the rock cores inside. Among the techniques currently being tested by the team is brazing, which involves melting a metal. alloy in a liquid that essentially sticks the metal together. Brazing can seal the sample container at a temperature high enough to sterilize any dust that may remain in the joint.
“One of our biggest technical challenges right now is getting a few inches away from the metal that is melting at around 1000 degrees. Fahrenheit (or 538 degrees Celsius), we need to keep these extraordinary samples of Mars below the highest temperature they’ve ever known on Mars, which is around 86 degrees Fahrenheit (30 degrees Celsius), ”said Brendan Feehan, the engineer Goddard system for the system that will capture, contain, and deliver the samples to Earth aboard the ESA Orbiter. “The first test results of our soldering solution confirmed that we are on the right track. “
Careful design by Feehan and his colleagues would allow heat to be applied only where it is needed for soldering, limiting the flow of heat to the samples. Additionally, engineers could insulate the samples in a material that will absorb heat and then release it very slowly, or they could install conductors that direct heat away from the samples.
Whatever technique the team develops, it will be essential not only for Martian samples, Glavin said, but for future sample return missions to Europe or Enceladus, “where we could collect and return samples from. cool ocean plumes that could contain living alien organisms. So we have to understand this. “
NASA’s rigorous efforts to eliminate the risk of harmful Earth contamination date back to the 1967 International Outer Space Treaty, which calls on nations to prevent the contamination of celestial bodies by Earth organisms and to prevent contamination of the Earth through returned samples. To safely return a Martian sample to Earth, NASA is partnering not only with ESA, but also with at least 19 U.S. government departments and agencies, including the U.S. Centers for Disease Control and Prevention and the US Department of Homeland Security.